Elution of enhanced truncated cys-less arrestin-1 eVSA-QH-Tr (C63V, C128S, C143A, K257Q, E346H; 1-378; this is bovine cys-less arrestin-1 analogue of the most potent in terms of Rh* binding mouse mutant (Vishnivetskiy et al., 2013)) from heparin-Sepharose. Coomassie gels (left panels) do not allow unambiguous identification of fractions to pool, so it is necessary to rely on Western blots (right panels). M, molecular weight markers; S, protein precipitated by ammonium sulfate and then dissolved and loaded onto heparin-Sepharose; Pt, pass-through; W, wash; fraction numbers are shown (numbers greater than 40 indicate high-salt wash).